MATLAB: Repetitive values for x axis

axisplot

How can I get this behaviour for the x-axis?

Best Answer

One way to plot 3 lines that share x-coordinates is to plot the lines individually. That's shown in the first subplot below.

A second way is to create 1 vector of x and y coordinates where NaN values are used to separate and disconnect the lines. That's shown in the second subplot below.

The very strange and difficult to interpret x-tick marks that repeat is thankfully not an option in Matlab but you can change the x-tick labels. In the two demos below, the actual x ticks range from 0 to 20, monotonically. Then I change the labels.

x0 = 0 : .5 : 10; 
x1 = x0 + 5; 
x2 = x1 + 5; 
y = x0*10; 
clf
subplot(1,2,1)
hold on
plot(x0,y, 'r-')
plot(x1,y, 'r-')
plot(x2,y, 'r-')
grid on
set(gca, 'XTick', 0:2:20, 'XTickLabels', [0 5 0 5 0 5 0 5 10 15 20])
subplot(1,2,2)
x = [x0, nan, x1, nan, x2, nan]; 
y = repmat([y,nan], 1, 3); 
plot(x,y, 'r')
grid on
set(gca, 'XTick', 0:2:20, 'XTickLabels', [0 5 0 5 0 5 0 5 10 15 20])

Related Solutions

MATLAB: Labels not showing for subplots – using xTicks xTickLabels

You forgot to specify the x-coordinates in plot(). Try this

%% Plotting problem
figure
subplot(6,1,1)
%figure





plot(1:one_plot, X(1:one_plot))
set(gca, 'XTick', hour_sub1, 'XTickLabel', tick_label_1);
ylim([0.0, 3])
subplot(6,1,2)
%figure
plot(one_plot+1:2*one_plot, X(one_plot+1:2*one_plot))
set(gca, 'XTick', hour_sub2, 'XTickLabel', tick_label_2)
ylim([0.0, 3])
subplot(6,1,3)
%figure
plot(2*one_plot+1:3*one_plot, X(2*one_plot+1:3*one_plot))
set(gca, 'XTick', hour_sub3, 'XTickLabel', tick_label_3)
ylim([0.0, 3])
subplot(6,1,4)
%figure
plot(3*one_plot+1:4*one_plot, X(3*one_plot+1:4*one_plot))
set(gca, 'XTick', hour_sub4, 'XTickLabel', tick_label_4)
ylim([0.0, 3])
subplot(6,1,5)
%figure
plot(4*one_plot+1:5*one_plot, X(4*one_plot+1:5*one_plot))
set(gca, 'XTick', hour_sub5, 'XTickLabel', tick_label_5)
ylim([0.0, 3])
subplot(6,1,6)
%figure
plot(5*one_plot+1:size(X), X(5*one_plot+1:size(X)))
set(gca, 'XTick', hour_sub6, 'XTickLabel', tick_label_6)
ylim([0.0, 3])

MATLAB: Do the x-tick labels overlap when I update them in a plot created using PLOTYY

Using PLOTYY creates two overlapping X-Axes along with the desired set of Y-Axes.

Subsequently changing the x-tick labels using DATETICK or set(gca, ‘XTickLabel’, …) only changes the x-tick labels of one of these two x-axes resulting in the overlap.

In order to work around this issue, you can delete the tick labels from both sets of x-axes and then assign new x-tick labels. The following code illustrates this workaround:

x=[1:10]
y1=2*x;
y2=3*x;
plotyy(x, y1, x, y2)
[AX,H1,H2] = plotyy(x, y1, x, y2)  
set(AX, 'xTickLabel','') % delete the x-tick labels
datetick('x',2) % update the x-tick labels

In the above code, [AX,H1,H2] = plotyy(...) returns the handles of the two axes created in AX and the handles of the graphics objects from each plot in H1 and H2. AX(1) is the left axes and AX(2) is the right axes.

Alternatively, you can set the dateticks on both axes, as in the example below:

x = datenum(0:0.01:20); 
y1 = 200*exp(-0.05*x).*sin(x); 
y2 = 0.8*exp(-0.5*x).*sin(10*x); 
AX = plotyy(x,y1,x,y2,'plot'); 
datetick(AX(1),'x',20) 
datetick(AX(2),'x',20)

Another option is to link the properties of both axes as shown in the example below:

x=[1:10];
y1=2*x;
y2=3*x;
[AX,H1,H2] = plotyy(x,y1,x,y2,'plot');
linkprop(AX,{'Xlim','XTickLabel','Xtick'});           % Link the limits of both axes, and the labels
axes(AX(2));datetick('x',20)                            % Now use DATETICK
axis tight

Best Answer

Related Solutions

MATLAB: Labels not showing for subplots – using xTicks xTickLabels

MATLAB: Do the x-tick labels overlap when I update them in a plot created using PLOTYY

Related Question